<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let teacher = {
            userName : 'fengjiaxin',
            age : 18,
            gender : 'man'
        }
        console.log(teacher)
        console.log(teacher.userName);
        teacher.hobby = '打篮球'
        console.log(teacher.hobby);
       
    </script>
</body>
</html>